Fitness trackers and smart watches have become a staple of modern life, with well over 100 million Americans using these devices to monitor their health.
More recently, they’ve gained popularity with children, many of whom will no doubt head back to school after the holiday sporting their very own unsightly high-tech wristwear.
Researchers have uncovered vulnerabilities that allow unauthorized users to track children’s movements or even communicate with them directly.
But while the health benefits are touted, the risks — both visible and hidden — are mounting.
A recent study from the University of Notre Dame revealed a rather shocking truth: These devices are loaded with toxic chemicals. Many fitness tracker bands contain per- and polyfluoroalkyl substances, commonly known as “forever chemicals” due to their near-indestructible nature.
Expensive bands, ironically marketed for quality, often have the highest levels of these harmful substances.
What makes PFAS dangerous?
PFAS are aptly named “forever chemicals” because of their nearly indestructible chemical structure, which prevents them from breaking down in the environment. These chemicals build up in soil, water, and even the human body over time.
Exposure to PFAS has been linked to various health issues, including cancer, hormonal disruptions, developmental delays in children, and weakened immune systems.
Among the most troubling effects is the potential for hormonal disruption, particularly in men, where PFAS exposure has been associated with plummeting testosterone levels. Given that testosterone plays a critical role in male health — affecting everything from energy levels to muscle mass and mental well-being — this trend is deeply concerning.
For wearable devices, the problem lies in dermal absorption — the process by which these chemicals seep into the skin during prolonged contact. Since wearables are often worn for hours, if not around the clock, the skin acts as a direct pathway for these harmful substances to enter the body.
Alarming findings
The study found that the pricier the band, the greater the risk.
Bands costing over $15 were more likely to have high concentrations of PFAS. Expensive watchbands, often made of fluoroelastomers, a synthetic rubber, had some of the highest levels of PFHxA. In fact, some samples contained PFAS concentrations exceeding 1,000 parts per billion — unprecedented levels compared to most consumer products tested.
To put this in perspective, PFAS levels in drinking water are considered concerning at just four parts per trillion, a fraction of what was found in these fitness bands. This means the chemical concentrations in some bands are astronomically higher than what is considered safe in other contexts.
Lower-cost bands were not entirely free of risk, but generally contained much lower levels of fluorine, the telltale marker for PFAS.
Health risks are not theoretical
The danger of PFAS in wearables isn’t merely hypothetical. Previous research indicates that PFAS can transfer through the skin, particularly when the skin is warm or sweaty — common conditions when wearing a fitness tracker during exercise.
Add to this the growing use of these devices by children, whose developing bodies are more susceptible to chemical exposure, and the problem becomes even more concerning.
Exposure to these chemicals can interfere with growth, disrupt puberty, and alter critical hormonal pathways, potentially leading to long-term health problems. The fact that children often wear these devices for extended periods compounds the risk, turning what might seem like a harmless gadget into a hidden health threat. Given that these chemicals accumulate over time, the risks compound with prolonged exposure.
Spy watches
But the dangers don’t stop at chemical exposure. These wearables are also a data goldmine, generating vast amounts of personal information.
From your heart rate to your precise location, these devices collect and transmit data constantly. Questions about who has access to this information — and how it’s used — are pressing. Fitness apps and manufacturers often share data with third parties, ranging from advertisers to data brokers.
In some cases, governments and law enforcement agencies can request access. Transparency is lacking, leaving consumers in the dark about how their data might be monetized, analyzed, and abused.
Another alarming risk is the potential for misuse of location data. Devices often upload workout routes to public platforms, ostensibly to help users track their progress or compete with others.
However, this visibility creates vulnerabilities. Predators or cybercriminals can analyze patterns to determine when and where someone is likely to be. A notable case in 2018 exposed U.S. military bases through fitness tracker data shared publicly, demonstrating how these devices can inadvertently reveal sensitive information.
Kids are especially vulnerable
The risks are magnified for children.
Parents buy GPS-enabled smartwatches to ensure safety, but many such devices are riddled with security flaws. Researchers have uncovered vulnerabilities that allow unauthorized users to track children’s movements or even communicate with them directly.
Such lapses in security expose children to potential exploitation. These concerns are not speculative; incidents of smart toys and trackers being hacked have already been documented.
Watch out
Smart watches are not your friends; they’re sleek, seductive little time bombs.
They’re part CIA operative, part cyanide. Quite literally, they’re poisonous data exploiters strapped to your wrist.
The best thing you can do is take that watch off and toss it in the trash. At the very least, stop wearing it around the clock.
And if you have kids, keep these devices far away from them. Children don’t need fitness trackers; they need to run, play, and grow without being exposed to harmful chemicals and invasive surveillance. They might not thank you now, but when they’re old enough to understand the risks, they probably will.
John mac ghlionn, Smartwatch, Fitness tracker, Forever chemicals, Health, Consumer health, Pfas, Lifestyle